over heating my monster pro

[lind5]

hi guys i have a brushless gorrila max revo
i run a monster pro esc with rc monsters heatsink
the neu 2700 kv motor
strobe slipper ofna 51 t spur
17/18/20 t pinions
2x 7.4 /5000mah lipos i run them in series (14.8)
g max single speed converstion
40 series wheels with mulcher tyres
the problem is it doesnt matter what pinion i use i keep getting thermal cut off wich isnt good when its jumping
the lipos/motor /esc are all getting hot
i was told it might be the motor causing this so i was considering getting a new one but does any one have any more idears what i can do to solve this problem

cheers guys